Patent GB-546115-A (GB)
Title: Improvements in or relating to pipe anchors or tubing catchers for oil and like wells
IPC: E21B23/01
Filed: 1940-11-13
Abstract: 546,115. Catching and anchoring 'tubes in wells. STEVENS, A. H. (Byron Jackson Co.). Nov. 13, 1940, No. 16444. [Class 85] A pipe anchor or tubing catcher for oil &c. wells comprises. pipe-engaging jaws movable between contracted and expanded positions on a head, jaw-actuating means including a supporting member slidably and rotatably mounted on said head, friction shoes movable radially in spaced openings in the supporting member, and spring means between the supporting member and the shoes for urging the shoes radially outwards. In Figs. 1 and 3, interposed in the tubing string is a nipple 10, which may be in two parts to permit removal of the anchor 66, and which carries a catcher head 15 which is integral therewith, or separately formed and welded thereto through openings 16; the head 15 has stepped pairs of wedging surfaces 21, 22, co-operating with complementary surfaces of serrated slips 17. The slips have upper and lower tail pieces 30, 36, engaged by pairs of lugs 27, 33, to hold the slips in sliding engagement with the head; reins 39 have lower hooked ends 40 engaging eyes in the slips, and upper hooked ends 42 engaging slots in an actuator 43 supported on a spring 47 which is normally held compressed by the slips but which, if the tubing falls, is relieved of the weight of the slips and expands to force the latter into engagement with the well casing 1. Above the actuator is an inwardly bevelled collar 51 to catch falling articles and prevent detachment of the slips, the collar having fluid passages 53 and also having bayonet slots engaging lugs 54 on the nipple, a set screw 56 locking the collar. On the head, and below each pair of lugs 33, are ribs 61, 62, defining passages 63 leading to the slips and alternating with passages 64 terminating in shoulders 65. The anchor 66 is movable within limits relatively to the head 15 and comprises a sleeve with apertures in which are arranged shoes 96 pressed outwardly against the well casing 1 by loose bow springs 113, shoulders 99 limiting outward movement of the shoes; the anchor has upwardly projecting fingers 67 normally arranged below the passages 64 but which, on rotation and lowering of the drill string, enter passages 63 and engage the slips to move the latter into engagement with the casing. To ensure that such rotation of the drill string is always in the same direction and so obviate unscrewing of the pipe joints, a sleeve 71 is rotatably mounted on the head 15 and has pairs of ribs 74 with bevelled ends, a spring 80 tending to hold the ribs 74 against the depending ribs 61, 62; on rotating the drill string to bring the passages 63 over the fingers 67, the latter engage the ribs 74 and hold the sleeve 71, but when the drill string is lowered for operation of the slips, the ribs 74 are freed and the sleeve 71 snaps back into position to prevent the fingers 67 returning to the original passages 64. To ensure similar movements of the sleeve 71 in the event of failure of the spring 80, one or more cam lugs 85, Fig. 4, are provided within the anchor sleeve and co-operate with the ribs 74. In another form, Fig. 13, lugs 69<SP>1</SP> are provided on the head below the ribs 61<SP>1</SP>, 62<SP>1</SP>, lugs 69<SP>1</SP>, ribs 61<SP>1</SP>, 62<SP>1</SP>, and the anchor fingers 67<SP>1</SP> have interengaging cam faces whereby in the successive operations of the device, the fingers 67' pass from one passage 64<SP>1</SP> to a passage 63<SP>1</SP> to operate the slips and, on release of the latter, pass to the succeeding passage 64<SP>1</SP>.